There is a gradual increase in memory usage over time, which happens even without Syphon involved (≈ 30MB in 12 hours).
I’ll continue to leave the with-Syphon and without-Syphon versions running, and see if I can crash either of them.
It’s unlikely to be the cause, but you should delete the call to println() in draw() to eliminate it as a possible contributing factor.
As yet I see no reason to suspect Syphon is to blame.